The invention relates to seats, and more particularly seats of cars provided with a base and with a back which can be tilted back and folded forward as desired.
In the automobile industry, it is traditional to equip vehicles with front seats in which the back can tilt relative to the base. These backs can, usually, be tilted backwards so as to improve the comfort of the occupants when driving or when resting. Sometimes the tilting of the backs may even be total, backwards virtually to the horizontal, so as to convert the seat into a bunk. In other cases, the back can also be pivoted completely forwards so as to bear against the base so as to free a substantial space.
As is known, in order to achieve the above whilst respecting safety, the back must be articulated relative to the base using a device for adjusting the tilting which must be absolutely effective, in other words once the choice of the relative tilting has been made, the back cannot alter its orientation even in the event of violent forces such as those which may result from an impact. A device for adjusting the tilting which meets the criteria thus briefly mentioned is, for example, that which is described in French Patent 2,463,596.
Although this type of seat is in general satisfactory to users, it is, however, not universally usable. For in some circumstances it is necessary or useful, or even desirable, to be able to have available an approximately horizontal shelf.